The Tor Browser / file comparison
comparison: gfx/skia/trunk/src/core/SkBitmapProcState_utils.h
gfx/skia/trunk/src/core/SkBitmapProcState_utils.h
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
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| -1:000000000000 | 0:ba92b6636d61 |
|---|---|
| 1 #ifndef SkBitmapProcState_utils_DEFINED | |
| 2 #define SkBitmapProcState_utils_DEFINED | |
| 3 | |
| 4 // Helper to ensure that when we shift down, we do it w/o sign-extension | |
| 5 // so the caller doesn't have to manually mask off the top 16 bits | |
| 6 // | |
| 7 static unsigned SK_USHIFT16(unsigned x) { | |
| 8 return x >> 16; | |
| 9 } | |
| 10 | |
| 11 /* | |
| 12 * The decal_ functions require that | |
| 13 * 1. dx > 0 | |
| 14 * 2. [fx, fx+dx, fx+2dx, fx+3dx, ... fx+(count-1)dx] are all <= maxX | |
| 15 * | |
| 16 * In addition, we use SkFractionalInt to keep more fractional precision than | |
| 17 * just SkFixed, so we will abort the decal_ call if dx is very small, since | |
| 18 * the decal_ function just operates on SkFixed. If that were changed, we could | |
| 19 * skip the very_small test here. | |
| 20 */ | |
| 21 static inline bool can_truncate_to_fixed_for_decal(SkFractionalInt frX, | |
| 22 SkFractionalInt frDx, | |
| 23 int count, unsigned max) { | |
| 24 SkFixed dx = SkFractionalIntToFixed(frDx); | |
| 25 | |
| 26 // if decal_ kept SkFractionalInt precision, this would just be dx <= 0 | |
| 27 // I just made up the 1/256. Just don't want to perceive accumulated error | |
| 28 // if we truncate frDx and lose its low bits. | |
| 29 if (dx <= SK_Fixed1 / 256) { | |
| 30 return false; | |
| 31 } | |
| 32 | |
| 33 // We cast to unsigned so we don't have to check for negative values, which | |
| 34 // will now appear as very large positive values, and thus fail our test! | |
| 35 SkFixed fx = SkFractionalIntToFixed(frX); | |
| 36 return (unsigned)SkFixedFloorToInt(fx) <= max && | |
| 37 (unsigned)SkFixedFloorToInt(fx + dx * (count - 1)) < max; | |
| 38 } | |
| 39 | |
| 40 #endif /* #ifndef SkBitmapProcState_utils_DEFINED */ |
